Aralkyl-para-aminophenol.



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PAUL REHLANDER, F OHARLOTTENBURG, GEE

. AUF ACTIEN (VORM. SCHERING),

IANY, ASSIGNOR TO CHEMISCHE FABRIK OF BERLIN, GERMANY.

ARALKYL-PARA-AMINOPHENOL.

Application filed September 28,

i To all whom it ma/y concern:

, velopers, of which the following is a specification. p I

I have found that the condensation products from the aromatic aldehydesand paraamino henol can easily and promptly be reduced y zinc andalkali, and that in this way aralkyl para aminophenols are obtainedwhich possess excellent developing properties.

The new bodies answer the formula in which formula R represents anaromatic radical. They are difiicultly soluble in water, soluble inether, alcohol and caustic alkalies, and possess both a character ofphenol and abasic character, thereby forming the corresponding salts.

Examples.

1'. Preparation of benzyl am aminophenoL-30 grams of benz-para-aminophenol (see Ber'ichte der Deutscli cn ChemischenGcsellschaft, Vol. 25, page 2753) are dissolved in an excess of soda lyeand then 15 grams of zinc dust are added. After 8 hours continuousstirring the yellow appearance disappears slowly, the reduction iscompleted and the mixture has a light gray color. While cooling so muchacid is added as to render the soda lye neutral, the liquid is thendrained off and the solid precipitate ex-' tracted by ether. After thedistillation of the ether, the new base remains and may be obtained pureby recrystallization from 50% methyl alcohol.- The reaction can berepresented by the following equation:

(),,H .()H N.C H OH Zn H O 4 O H CH NHE HQH Z110.Benzyl-para-aminophenol melts at about 89 centig'rade. It is difficultto dissolvein water, in ligroin and alkali carbonate, but isSpecification of Letters I atent.

1907. Serial No. 395,049. (Specimens) is -drained of? and dissolved inWater.

Patented May 18, 1909.

alcohol, ether, benzol and caustic allralies. Ihe chlorhydrate is easilysoluble in hot water, difiicultly soluble in cold water, while theacetate is easily soluble in cold water.

In the same way other condensation products from aromatic aldehydes andparaaminophenol can easily be reduced.

2. jrnisyl-para-aminophenol (methyloxyeasily soluble in-benzyl-paraeaminophenol) is best obtained in the following manner: 12grams of. anisylidene-para-aminophenol (see Ber'ichte der DcutschcnChem. Gcs. Vol. 25, page 2754) are well stirred with 40 cubiccentimeters dilute soda lye of about 15 per cent. NaOH and 15 cubiccentimeters -a cohol and then for 5 hours with 6 grams of zinc dust at60 centirade. Then the mixture is warmed and lltGIGd. On cooling thesodium compound of the anisyl-para-aminophenol separates as flakes withagolden color. The compo i ilrlid 1s solution, when neutralized withhydrochloric-acid gives the free base, which, when recrystallized from50 per cent. methyl alcohol, melts at about 102 to 103 centigrade.

While the base itself has a similar solubility to thebenzylpara-aminophenol, its salts are much more easily soluble.

3. Salicyl -'para aminophenol (orthoxybenzyl-para-aminophenol) can beproduced in a similar way from salicylideneara-aminophencl (seeBer'ichte der Deutsc en Chem. Ges. Vol.25, page 27 54) and melts,recrystallized'from benzol, at about from 122 to 123 centigrade. Thebase is difiicultly soluble in water, easily soluble in methyl and ethylalcohol and in hot benzol. The salts are. easil soluble in water and canbe precipitate from the watery solution by com mon salt. The precipitateis at first an oily mass, however soon sets.

As already mentioned the aralkyl-paraaminophenols possess excellentdeveloping properties, Their salts better res/1st the action of the airand can'therefore be better preserved than the sulfate ofmethyl-paraaminophenol known as methyl; A further advantage is that theydo not attack the hands of the photographer.

4. For a ready made developer, using benzyl-para-aminophenol forinstance, the following composition is advisable: In 900 cubiccentimeters of water are dissolved 100 grams crystal soda, 25 gramsanhydrous soda sulfite. Then add 6 grams hydroquinone, 0.4 gramspotassium bromid, 2 grams benzylparaaminophenol chlorhydrate. Preferablythe latter is first dissolved in 100 com. water. A precipitate is formedwhich will dissolve on the addition of dilute soda lye, containing 2.1grams NaOH, in drops and shaking. A good result can also be obtainedwithout soda lye by using 40 grams of trisodium phosphate in place ofthe mentioned 2.1 grams NaOH and omitting the sodium carbonate. In placeof the benzy1 ara-aminophenol other aralkyl-aminopheno s can be used.

Benzyl para-aminophenol, anisyl araaminophenol and salicyl-para-aminopenol form salts with caustic alkalies which are easily soluble in waterbut which dissolve fvith difliculty in concentrated caustic alkaies.

Having now described my invention and in what manner the same is tobe'performed, What I claim as new and desire to secure by Letters Patentis:

1. The herein described new substance constituting analkyl-para-aminophenol 311',

niatically substituted in the alkyl group,

which process consists intreating the condensation product from aromaticaldehyde and para-aminophenol with zinc and alkali and isolating theproduct so formed, substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

PAUL REHLANDEIL Witnesses:

WOLDEMAR HAUPT, HENRY HASPER

